The purification of DNA to a degree of purity suitable for further use, for example, amplification or processing with restriction enzymes, probe hybridization, cloning and so forth, is a well-known procedure (See, e.g., M. Ausubel et al., Eds., Current Protocols in Molecular Biology, Chapter 2, Section I.1-I.4, Wiley, 1989). These procedures lend themselves to rapid processing and automation, so long as the source of the DNA does not require physical grinding or maceration to disrupt cells or tissue; for example, DNA from biological fluids.
A need therefore exists to rapidly and reliably purify DNA from sources that require grinding or maceration to release DNA into solution (hereinafter referred to as "solid samples" for brevity). These samples, e.g., from plant, animal or microorganism sources, leave insoluble tissue or cellular material as by-products of the purification process.
The purification of DNA from these sources is considerably more difficult and time-consuming than from biological fluids, since another phase separation step (the solid from the liquid phases) is needed (see M.W. Lassner, P. Peterson and J.I. Yoder Plant Molecular Biology Reporter, 72, 112-128 (1989). Techniques for automating such processes are lengthy and normally employ centrifugation to separate phases. These requirements have prevented the development of commercially viable, fully automated protocols for the purification of DNA from plants, animals and microorganisms when mechanical disruption is needed to release DNA from the samples.